1. Field of the Invention
The present invention relates to an external filtration device particularly for aquariums and ornamental water tanks, of the type including a hermetically closed container that internally accommodates a pump and a filtration chamber which are connected to the outside by a suction connector and a discharge connector.
2. Description of the Prior Art
As is known, in devices of the above indicated type the suction and discharge connectors are generally connected to the tank of the liquid to be filtered by virtue of ordinary flexible hoses.
These devices should open in order to allow periodic maintenance of the filter. Accordingly, such devices are generally composed of two parts that can be coupled hermetically by locking hooks or other manual closure devices.
In some known devices, the container is formed by a lower cup-shaped part adapted to receive a filter cartridge and by an upper part or lid that encloses an electric pump together with the suction and discharge connectors. The pump can be arranged upstream or downstream of the filter component.
In order to ensure pump startup, the pump must be primed by keeping the impeller constantly submerged, avoiding if possible the forming of air pockets in the ducts.
In a known device provided with an upstream pump, the pump is located at the base of the container. This arrangement facilitates the priming of the pump but causes unfiltered liquid to flow through some of its internal components, with consequent greater wear and risk of seizing. Furthermore, the pump can be rather noisy, especially after an initial period of use.
In another conventional device the pump is arranged downstream of the filtration component, for example built into the lid, and in order to prime the pump it is necessary to first of all fill the container with liquid and expel the air from the circuit.
Both arrangements have drawbacks that compromise the durability and efficiency of the pump or the practicality and functionality of the device as a whole.
An additional drawback of conventional external filtration devices arises from the components for closing the container, which are generally constituted by lever-like hooks. These components are in fact difficult to operate and do not have an easily identifiable open or closed position. This can cause unintentional opening of the device and therefore accidental leakage of the liquid contained in the device, consequently forcing one to repeat the pump priming operations.
The aim of the invention is to eliminate the drawbacks described above by providing an external filtration device, particularly for aquariums and ornamental water tanks in general, that can be easily primed from the outside without complicated and troublesome operations.
An object is to provide an external filtration device that can be opened easily for inspection and maintenance and unequivocally visualizes its open or closed condition, so as to avoid accidental opening on the part of the user.